Spraying device for liquids



Nov. 7, 1950 E. w. VOSE 2,528,927

SPRAYING DEVICE FOR LIQUIDS Filed Dec. 7, 1944 III/IA'IIIJ VII K INVENTOR. 23

EDW/N w. VUSE 'T Val/W ATTORNEYS.

Patented Nov. 7, 1950 SPRAYING DEVICE FOR LIQUIDS Edwin W. Vase, Orange, N. J., assigncr to Spray Process 00. Inc., New York, N. Y., a corporation of New York Application December 7, 1944, Serial No. 567,033

2 Claims.

This invention relates to Improvements in Spraying Devices for Liquids and has for an object the provision of a liquid sprayer simple in form, adapted to be manufactured at extremely low cost, and adapted to be operated by air from a large volume, low pressure source.

Another object of the invention is the provision of a liquid sprayer including a straight air tube, a small conduit connected thereto where the pressure is substantially maximum and leading to a container of liquid to be sprayed for impressing pressure on the surface of the liquid; an injector extending into said tube and spaced apart from the discharge end thereof a predetermined distance to form a mixing chamber between itself and said discharge end; a conduit extending from the bottom of said container and connected to deliver liquid to said injector, and means in the discharge end of said tube for aiding the mixing of the air and liquid and for defining the cone of mixed air and liquid discharged.

A further object of the invention is the provision in a liquidsprayer, of swivel means in the liquid line permitting the discharge from the air tube to be directed in a plurality of directions, the container of liquidremaining undisturbed.

Yet another object of the invention is the provision in the liquid line of a threadedscrew for restricting the passage, or interior bore thereof, said screw being of substantially the diameter of said bore, and its end substantially conforming to the interior wall of said bore, whereby liquids (particularly light liquids) are broken up into a plurality of fine streams defined by at least some of said threads, under the urge of the pressure exerted on theliquid supply in the container and by the sub-atmospheric pull generated at the injector in the nozzle or air tube.

Other objects and advantages of the invention will become apparent to those skilled in the art.

Referring to the drawings, which are given by way'of example only:

Figure 1 is a perspective view of a'complete liquid sprayer and its motor driven blower for supplying a large volume of air at a low pressure at the sprayer;

Figure 2 is a cross-sectional view of the end of the nozzle or air tube, showing details of the injector and the removable member for defining the mixing chamber; V

Figure 3 is a sectional view taken along the lines 3-3 of Figure 2;

Figure 4 is a fragmentary elevation of a portion of Figure'2, showing a valve for adjusting the quantity of liquid delivered via the injector; and

Figure 5 is a cross-sectional view taken alon the line 5--5 of Figure 4.

My novel sprayer includes a liquid container or tank II] which carries at least one hook II which may engage a suitable harness l2, WOlll by the operator. The tank It! may also be provided with a handle l3 at the top. The top of the tank is also provided with a suitable filler hole, closed by a cap l4, and a fitting l5 may be soldered or brazed to the top with its interior bore communicating with the interior of the tank, the solder being shown at 16.

A bushing I1 is soldered or brazed to a wall of the tank near the bottom thereof. This bushing has a threaded hole formed therein communicating with the interior of the tank, and a shut-off valve l8 has a threaded shank which is screwed into the bushing IT. The other shank of the valve [8 has one end of a hose I9 secured thereto by means of a clamp 20.

The other end of the hose l9 embraces a nipple 2i and is secured thereto by a clamp 22. The

nipple 2| threadedly engages an elbow 23, the other end of which threadedly engages the outer end 24 of an injector tube 25, which will be presently described.

An air tube, or nozzle, 26, has several radial holes 2! in alignment near one end thereof. The end 28 of a flexible conduit 29 forms a working fit on the end of the air tube 26, and may be adjusted to cover or uncover one or more of the holes 21 in order to control the air pressure, as will presently be described. The other end 30, of the flexible conduit 29, is connected to the discharge nozzle 3 I, of the motor driven blower unit 32. This blower unit may be provided with a suitable handle 33 and may have aconveniently located switch 34 for controlling the motor.

The injector tube 25, above referred to, has a beveled face 35 and is mounted in a hole 36 formed near the end 3'! of the air tube 26. Within the end of the air tube 2% is bushing 33, the outside diameter of which forms a fit in the air tube 25, and a portion 32a of the interior bore of which is of reduced diameter and threaded, and defines, between its inner end and the beveled face 35, a mixing chamber for the air and the injected liquid. The bushing 38 has a hole 36a formed therein which is in alignment with the hole 36. The injector tube 25 extends through the aligned holes 35. 36a and is positioned with its beveled face 35 directed toward the end 37, of the air tube. A nut 39 is positioned on the injector tube in contact with the outer wall of the tube 26. This nut is brazed, or soldered, to the outer wall of the tube 25 and is also brazed, or soldered, to the outer wall the rear end of the bushing 48.

of the injector tube 25. A hole 48 is drilled in the nut 38 and through the wall of the injector tube 25 (see Figs. 3 and 5). This hole is threaded and the diameter of a screw 4|, fitting said threaded hole, is such that the outer diameter of the screw is substantially equal to the inner diameter oflthe injector tube 25. The end 42 of the screw is rounded to conform to the interior diameter of the injector tube 25. The screw 4! may be provided with a flat, elongated head 43 to enable the operator to turn it. Spaced apart from the injector tube 25, in the air tube 26, is a nipple 5' 3, which extends through a hole in the Wall of the air tube 25," and is'brazed thereto, as shown at 55. A flexible tube 45 has its upper end connected to the fitting l5 and its lower end connected to the nipple 55,.sothat when air is passing through the tube pressu reis exerted upon fluid in the tank It, above the surface thereof via the nipple 54, the tube 36 and the fitting I5. The air tube may be norj mally snapped into a clip ll, secured to a side wall of the tank it. Th tube may be disengaged from the clip and may be freely swung in several planes about the pipe threads on the end ofthe injector tube 25, which act as a swivel.

A bushing 43, externally threaded at one end the reof, having abore 39 formed therein of a predetermined diameter, and streamlined at the point 58, is-screwed into the bushing 38, and

when positioned therein is slightly spaced apart from, the beveled face of the injector tube. The space between the beveled face 35 and the streamlined portion 5!] of the bushing 48, forms a mixing chamber within the bushing 38, and restricts the stream of mixed air and liquid so that a deposit of predetermined size may strike the -work. Since the blower delivers a large volume of air at low pressure, applicant is, with this device, enabled to apply finishes to surfaces, such as thesurface [24' shown in Figure 1, much more rapidly and much more evenl than is possible to obtain with the usual blowguns employing'high pressure air at low volume.

The a r pressure impressed on the surface of fthej'liquid in the tank is taken from :a point at whichtheairpressure in the tube 26 is highest. Applicant, by restricting the air tube with the bt1shing88a short distance before the air encounters" the" injector tubeeffects a suction, or 'vacuum, upbn the beveled face 35 of the injector tube, which is of the order of 8" on a water column. The liquid delivered to the injector tube from the tank is, as pointed out above, un der pressure and the combined suction and pressure insure the delivery of a certain steady stream of liquid to meet the air stream in the chamber defined between the beveled face 35 and In this chamber the air and liquid are thoroughly mixed and as stated above, the interior bore 49, of the bushing 48, restricts the stream and narrows the diameter of the deposit upon the work.

.The screw 4! may be adjusted to regulate the flow of liquid through the injector tube. In usingsmall quantities of liquid and particularly liquids of low viscosity, the screw may be screwed cal.

down until its end 42 is in contact with the interior wall of the injector tube 25. When this is file of this patent:

done the stream of liquid is broken up into a plurality of small streams which pass through the VS of the threads and the interior wall of the injector tube. These streams are ejected with substantial force due to the fact that they are pulled through by th partial vacuum created at the beveled face 35, and they are pushed through by the pressure impressed upon the surface of the liquid in the tank.

What is claimed is:

1. In a device for spraying liquids, a nozzle comprised of an elongated tube having an inlet end, means to connect the said tube to a source of high volume low pressure air, means mounted on said tube intermediate the ends thereof for leading pressure from the interior of said tube to a container of liquid to be sprayed, :a tubular bushing mounted in the discharge end of said tube, a pairof aligned holes formed in the wall of said tube and in the wall of said bushing, a short length of pipe positioned in said aligned holes and secured to both said tube and said bushing, said pipe having a beveled face formed thereon communicating with its interior and facing the discharge end of said tube, a second tubular bushing extending into said nozzle from the dscharge end thereof and having its inner end spaced apart from said beveled face to form a mixing chamber; the interior of said second tubular bushing being smaller in diameter than the interior of said first tubular bushing to cause a slight compressing of the mixture of air and liquid as it leaves the discharge end of said nozzle.

"2. In a device for spraying liquids, a nozzle comprised of an elongated tube having an inlet end, means to connect the said tube to a source of high volume low pressure air, the interior diameter of said tube having a portion of reduced cross-section adjacent to the discharge end thereof, the interior of said" portion being parallel to the interior of said tube, a pipe eXtending into said tube and said portion, said pipe having its axis at substantially a right angle to the axis of said tube and having a beveled. portion facing said discharge end,.a fitting threadedly en- .gaging said pipe and forming therewith a swiving the diameter of the mixed stream. of air 7 and liquid ,as it leaves said nozzle.

EDWIN w. vosE.

REFERENCES CITED are of record in the The following references V UNITED STATES PATENTS Number" Name 1 ,Date

322,908 Corbly, July 28, 1885 584,864 Fisher June 22, 1897 726,249 Brachhausenv Apr. 28, 1903 1,338,679 Davison MayJl, 1920 1,806,784 Breuer ,May'26, 1931 1,881,570 Hermann .-Oct. 11, 1932 2,343,163 Vose Feb. 29, 1944 2.399.081 Vose pr. '23. 1946 

